1. Field of the Invention
The present invention relates to a hard disc, and more particularly, to a method of and an apparatus for preventing off tracking from occurring when a hard disc drive operates.
2. Description of the Related Art
An increase in a recording density of a hard disc requires a precise positioning of a servo writer that writes a servo signal on the hard disc.
In general, a track is formed by servo signals that are written on the hard disc by the servo writer. To form tracks of even widths on the hard disc, the servo writer must precisely write the servo signals on the hard disc. That is, the servo writer is required to move along the track accurately without swaying during writing the servo signals on the hard disc. If the servo signals are not precisely written on the hard disc, i.e., the servo writer is shaken during writing of the servo signals, it is disadvantageous that the tracks of different widths are obtained from the hard disc. When the widths of the tracks are not uniform, a position of data to be accessed by a head (not shown) of a hard disc drive may be changed when the head writes or reads data on or from the track. For instance, when the head is positioned on an n+1th track, the data will be certainly recorded on an n−1th track if the width of each track is even. However, if the head is positioned at the n+1th track, and the width of nth track is narrower than those of other tracks, the data may be recorded in a border region between the n−1th track and n−2th track. Further, if the head is positioned at the n+1th track, and the width of nth track is wider than those of other tracks, the data may be recorded in another border region between the nth track and n−1th track. Accordingly, the tracks of uneven widths may result in occurrence of off tracking that causes the data to be recorded in the border region between the tracks.